When you ran sudo yum install ImageMagick, you only installed the core ImageMagick binaries. The PHP extension needs separate installation. Here's how to verify the current state:

php -m | grep imagick
# If no output, the extension isn't loaded

php -i | grep -i imagick
# Checks if it's even compiled

For Amazon Linux (based on CentOS/RHEL):

sudo yum install php-pear php-devel gcc
sudo pecl install imagick
echo "extension=imagick.so" | sudo tee /etc/php.d/imagick.ini
sudo service httpd restart

Symfony 1.4 often runs on older PHP versions. If you're using PHP 5.x:

sudo yum install php56-pecl-imagick   # For PHP 5.6
# OR for PHP 7.0:
sudo yum install php70-pecl-imagick

Create a test script to verify functionality:

<?php
if (extension_loaded('imagick')) {
    $imagick = new Imagick();
    $version = $imagick->getVersion();
    echo "IMagick works! Version: " . $version['versionString'];
} else {
    echo "IMagick NOT loaded!";
}
?>

On some EC2 instances, you might need additional dependencies:

sudo yum install ImageMagick-devel
sudo ldconfig /usr/local/lib

Check Apache error logs if issues persist:

sudo tail -f /var/log/httpd/error_log

In your config/ProjectConfiguration.class.php:

if (extension_loaded('imagick')) {
    sfConfig::set('sf_image_adapter', 'imagick');
} else {
    throw new sfException('IMagick extension required');
}

For batch image processing in tasks:

$image = new sfImage('input.jpg', 'image/jpeg', 'imagick');
$image->resize(800, 600);
$image->saveAs('output.jpg');

When deploying Symfony 1.4 applications on Amazon EC2, many PHP developers encounter this familiar roadblock - the system has ImageMagick installed but the PHP extension isn't properly configured. The key distinction here is between the ImageMagick binaries (which you installed via sudo yum install ImageMagick) and the PHP extension that provides the IMagick class.

First, let's check what's actually installed on your EC2 instance. Run these commands sequentially:

# Check ImageMagick binaries
convert --version

# Check PHP modules
php -m | grep imagick

# Alternative check for installed PHP modules
php -i | grep imagick

If you don't see 'imagick' in the output, you'll need to install the PHP extension separately.

The process differs based on your PHP version. For most EC2 instances using Amazon Linux:

# Search for available packages
sudo yum search php-imagick

# Install for PHP 7.x (common on newer instances)
sudo yum install php-imagick

# For PHP 5.x (which Symfony 1.4 often requires)
sudo yum install php56-imagick

# Restart your web server
sudo service httpd restart

Sometimes the extension installs but doesn't get enabled. Check your php.ini:

# Find your php.ini location
php -i | grep "Loaded Configuration File"

# Then add or uncomment this line
extension=imagick.so

If you're still having problems, try these diagnostic steps:

# Verify the extension is loaded
php -r "phpinfo();" | grep imagick

# Check for version mismatches
php -r "echo Imagick::getVersion()['versionString'];"

# Test basic functionality
php -r "$im = new Imagick(); echo 'IMagick works!';"

For Symfony 1.4 projects, you might need to explicitly check the extension in your configuration:

// In config/ProjectConfiguration.class.php
if (!extension_loaded('imagick')) {
    throw new sfException('IMagick extension not loaded');
}

// Or in a filter/action
try {
    $imagick = new Imagick();
    // Your image processing code
} catch (ImagickException $e) {
    sfContext::getInstance()->getLogger()->err($e->getMessage());
}

If you absolutely can't get IMagick working, you can fall back to command-line ImageMagick:

$source = '/path/to/image.jpg';
$output = '/path/to/output.jpg';
$command = "convert {$source} -resize 800x600 {$output}";
exec($command, $output, $returnCode);

if ($returnCode !== 0) {
    // Handle error
}